I have a 95 Blazer 4dr 4x4 4.3L CPI blah blah blah.

Anywho, here's my issue.

I'm in the Army, and we went to the field on Monday. My truck worked just fine before I left. So I went to the field, came back on Thursday, tried to start my truck, and she wouldn't start. She was cranking but just wouldn't turn over. I ruled out fuel pump cuz I hear it engaging and I smell fuel in the engine bay. My buddy also checked each wire for spark and all 6 cylinders have spark.

I tried again today to start it and I heard a really loud misfire that sounded like a gunshot.

Please help. I need my truck!!!

 

Flip,
From what I've been learning on this forum, on of the first things you should do is a fuel leakdown test. The link below is a thread that describes how to do this and how it is a good place to start. The search box above is useful also. Just type in fuel leakdown. You didn't note if you have a Service Engine Soon (SES) light on or not?

https://blazerforum.com/forum/engine...problem-75029/

 

I haven't had a light. I didn't have one before I went to the field and I still don't have one.

 

What I should have stated was "did you have a light before you went to the field?". I would follow that thread I sent on the previous post. My understanding is that is the first practical troubleshooting step before you start wasting money replacing parts until you find the right one.

You do have an SES light when you first turn they key and then goes out....yes?

Backfires in my experience are usually a timing issue. But I would still start with the fuel leakdown test first. There's a guy named "Captain Hook" on these forums who knows these vehicles inside and out. He is one that seems to always recommend the fuel leakdown test first.

 

cpi's are just notorious for fuel issues. Do this,spray some ether in the throttle body and turn the key,did she start up then die? if so,the regulator/spider is bad or pumps weak. they have to have at least 60 psi to run correctly. Dont do nothing else until you check the pressure with a actual gauge. you can rent one from autozone for free. just have to leave a retail deposit incase you never return it.

 

So basically, do a fuel pressure test. If I'm getting less than 60 psi, its more than likely my fuel pump, fuel filter, or injector?

And what do I do if my fuel filter is seized on? lol

 

There are primarily two things you want to check when you do the fuel pressure test: make sure the pressure gets high enough (55-60psi) and make sure once the pump is off the pressure holds for at least ten minutes without going below 55psi. If the pressure drops then you've got a leak somewhere.

If your filter is seized on then spray the inlet nut with PB Blaster or Bolt-Off and let it sit for a while. Get two wrenches and break it loose gently.

 

So I did the pressure test and got the following results:

NO pressure.

So because of this, I'm going to go ahead and say it's the fuel filter. This is hard to determine for sure though, because I smell fuel under the hood, but if it's trickling in through the filter but isn't giving it enough to start, it could be valid.

Does anyone else have any ideas on what else it could be???

 

I have a 99 and it's different, but I lost pressure also and pulled off the fuel filter, while I had it off, I tried turning on the key on to get fuel squirting out and got nothing. Had to replace the fuel pump in the tank. Good Luck!

 

I guess that is a good test to see if the pump is actually working properly.

I've been doing a lot more research as well, and other people are saying it's the pump not working properly, or the fuel pressure regulator is sending fuel right back to the gas tank. i have NO IDEA where to start with this. Every job I do is gonna be costing me a ton of money, even the fuel filter (cuz its NOT moving at all, it's seized for good). I think I may just take it to a mechanic to diagnose the problem and see how much money I'm going to be dumping into her.